Libraries

jQuery - The de-facto library for the modern age. It makes things like HTML document traversal and manipulation, event handling, animation, and Ajax much simpler with an easy-to-use API that works across a multitude of browsers.

Backbone - Backbone.js gives structure to web applications by providing models with key-value binding and custom events, collections with a rich API of enumerable functions, views with declarative event handling, and connects it all to your existing API over a RESTful JSON interface.

Underscore - Underscore is a utility-belt library for JavaScript that provides a lot of the functional programming support that you would expect in Prototype.js (or Ruby), but without extending any of the built-in JavaScript objects.

lawnchair - Key/value store adapter for indexdb, localStorage and more

Plugins

jQueryUI - jQuery UI is a curated set of user interface interactions, effects, widgets, and themes built on top of the jQuery JavaScript Library.

Bootstrap - Bring Bootstrap's components to life with over a dozen custom jQuery plugins. Easily include them all, or one by one.

Async.js - Async is a utility module which provides straight-forward, powerful functions for working with asynchronous JavaScript. Although originally designed for use with node.js, it can also be used directly in the browser. Also supports component.

timeago - Timeago is a jQuery plugin that makes it easy to support automatically updating fuzzy timestamps (e.g. "4 minutes ago" or "about 1 day ago").

Chosen - Chosen is a library for making long, unwieldy select boxes more friendly.

Tools

Bower - Bower is a package manager for the web. It offers a generic, unopinionated solution to the problem of front-end package management, while exposing the package dependency model via an API that can be consumed by a more opinionated build stack. There are no system wide dependencies, no dependencies are shared between different apps, and the dependency tree is flat.

Guides

Jasmine - Jasmine is a behavior-driven development framework for testing JavaScript code.

Building a Chrome Extension - Extensions allow you to add functionality to Chrome without diving deeply into native code. You can create new extensions for Chrome with those core technologies that you're already familiar with from web development: HTML, CSS, and JavaScript.

Backbone Tutorials - Backbone Tutorials is a collection of tutorials written by Thomas Davis.